Trueness and precision of different intraoral scanners for shade assessment under variable light conditions-a cross-sectional study

To compare the trueness and precision of shade assessment using different intraoral scanners under variable light conditions. To evaluate shade trueness and precision, color measurements (L*, a*, b*) were obtained using visual assessment, a spectrophotometer (SPM) (VITA Easyshade Advanced V), and two intraoral scanners, intra oral scanner-A(IOS-A) (Carestream 3700, Dexis IS ScanFlow) and intra oral scanner-B(IOS-B) (3Shape Trios 3), were used to scan 20 subjects by single assessor under natural daylight and operatory light. The color difference (ΔE) was calculated. Trueness and precision were assessed for each method across the two lighting conditions. Trueness of the test groups was compared by Analysis of Variance (ANOVA) followed by Tukey’s Post hoc Test for pairwise comparisons and precision by Kruskal Wallis test while pairwise comparison was done by Mann Whitney U Test. P values <0.05 was considered as statistically significant. For trueness, significant differences were observed among the visual method, IOS-A, and IOS-B. Tukey’s test revealed a significant difference between the trueness of IOS-A and IOS-B, while no significant differences were detected between the visual method and either scanner. Regarding precision, significant variations were found among the test groups. A significant difference was noted between the visual method and IOS-A, with a highly significant difference between IOS-A and IOS-B. However, no significant differences were observed between SPM and the visual method or IOS-B, nor between the visual method and IOS-B. IOS-B shows better precision for shade determination than IOS-A, while the visual method is more reproducible than IOS-A. No significant differences in trueness and precision were found between the visual method and IOS-B.